Lambda-Splittings and Line Intensities in the 3 <-- 1 Hot Band of 14N16O: The Spectrum of Nitric Oxide in the First Overtone Region

Intensities and Lambda-splittings have been measured for lines belonging to the 3 <-- 1 hot band of 14N16O. The vibrational transition moment and the Herman-Wallis coefficient have been determined. Hamiltonian constants have been calculated for the four vibrational states v = 0, 1, 2, and 3, and a synthetic spectrum has been generated in the first overtone region of NO, taking into account the hyperfine structure for the 2 <-- 0 band. Copyright 1998 Academic Press. Copyright 1998Academic Press

Lambda-Splittings and Line Intensities in the First Overtone of Nitric Oxide

Using Fourier transform spectra, absolute line parameters (positions, Lambda splittings, and intensities) have been measured in the two allowed subbands 2Pi1/2-2Pi1/2 and 2Pi3/2-2Pi3/2 of the 2 <-- 0 vibrational band of the 14N16O molecule. These line parameters have been compared with previous experimental results and with the values available in the current HITRAN database. The measured line intensities led to the determination of the transition dipole moment as well as the Herman-Wallis coefficients. Improved spectroscopic constants were also obtained for the v = 2 vibrational state. Copyright 1997 Academic Press. Copyright 1997Academic Press

Rotational and vibrational dependences of collisional linewidths in the nnu(2)-(n-1)nu(2) hot bands of H2O from Fourier-transform flame spectra.

The collisional widths of ~ 160 transitions belonging mainly to the 2nu(2)-nu(2), 3nu(2)-2nu(2), and 4nu(2)-3nu(2) hot bands of the H(2)(16)O molecule have been measured on Fourier-transform air-methane flame spectra at 2000 K and analyzed, showing a strong decrease in the collisional widths when the rotational quantum number J increases, as well as a nonnegligible decrease of the collisional widths when the nu(2) vibrational quantum number increases.

Measurements of collisional linewidths in the nu(2) band of H(2)O from Fourier-transformed flame spectra.

The collisional widths of more than 200 transitions belonging to the v(2) band of the H(2)O molecule were measured by using the Fourier-transformed spectra of an air-methane flame at 2000 K. A nonlinear least-squares method was used to determine the line widths for a wide range of J (up to 28) and K(a) (up to 14) quantum number values. Finally, an analysis of the results as functions of J and K(a) is presented.

Phase errors on interferograms: influence on the determination of positions, intensities, and widths of lines in the infrared.

The effect of a phase error on line parameter measurements by using Fourier-transform spectra is studied, showing that, to obtain accurate results without modifying the interferogram, it is necessary to adjust a computed spectrum to an experimental spectrum in which the phase error is taken into account.

Detection of rubella virus in amniotic fluid by electron microscopy.

We report in this paper the observation of rubella virus by electron microscopy in an amniotic fluid sample, collected from a pregnant woman with rubella infection. Virological investigations by inoculation of cell cultures with amniotic fluid and fetal blood remained negative, due probably to the presence of neutralizing antibodies in the samples. Electron microscopy is a rapid but weakly sensitive method to detect viruses in clinical specimens. However, this unusual observation would indicate that in some cases electron microscopy could be a useful technique to evidence a fetal rubella infection.

Cytomegalovirus viremia in HIV-infected patients treated with zidovudine.

We followed the course of cytomegalovirus (CMV) viremia in 65 patients treated with zidovudine for symptomatic HIV-1 infection. Blood samples were tested for the presence of CMV before initiation of treatment and every 3 months thereafter. 13 patients (20%) showed a positive CMV viremia at initiation of treatment. After 3 months of therapy, only 2 patients (3%) remained viremic. However, the frequency of CMV viremia increased from the 6th month of treatment and 28 (43%) of our patients showed a persistence of, or conversion to, positive viremia during the course of treatment. CMV viremia was associated with a decline in the patients' clinical state in 79% of the cases. In contrast, among the 37 patients, who remained negative for CMV viremia, 73% did not show a progression of the HIV-associated disease. The results suggest that CMV viremia could be considered as a useful marker for HIV-associated disease and its progression as well as for the efficacy of therapy.

Approaches to the diagnosis of viral pneumonias in the immunocompromised host: the importance of assaying cytopathogenic viral effects in bronchoalveolar lavage cells.

Pneumonopathic conditions in the immunocompromised host (IH) are frequent and often serious. Rapid diagnosis is essential and is made possible by bronchoalveolar lavage (BAL). Sixty-two pneumonopathic episodes in 53 immunocompromised patients were examined by BAL, for viral cytopathogenic effects (CPE) in isolated cells, with appropriate viral culture techniques. Viral culture was positive in seventeen of the eighteen episodes in renal allograft recipients and AIDS patients as against eight of the fourty-four episodes in other causes of IH (p less than 0.001). CPE was found thirteen times; in seven cases it was characteristic of cytomegalovirus. Positive viral culture and CPE were shown simultaneously during thirteen episodes in eleven patients. Ten patients died (autopsies performed in three cases confirmed viral presence). Positive viral culture with absence of CPE was observed in twelve cases. There were only four fatalities in this group (the autopsies performed in three cases did not establish the presence of a virus in the pulmonary parenchyma). The percentage of lymphocytes was high in both groups of patients (18.6 +/- 2.8%). CPE is a simple and rapid examination for the diagnosis of viral pneumonopathology in the IH. Prognosis at present is gloomy; more complex examinations such as viral cultures and/or identification of the virus by immunofluorescence will be indicated only when effective antiviral agents become available.

Production of MIF-like supernatants by rheumatoid arthritis lymphocytes stimulated by immunoglobulin G.

Patients with rheumatoid arthritis (RA), patients with positive tuberculin (PPD) skin-tests and controls were studied. The lymphocytes from these groups were cultured in serum-free medium to obtain cell-free supernatants. These lymphocyte cultures were pre-incubated with the appropriate antigen or reconstituted after removal of the cells. Supernatants from RA lymphocytes stimulated in vitro by IgG induced an inhibition of the leucocyte migration, as well as the supernatants from tuberculin-sensitized lymphocytes. However, supernatants from non-RA lymphocytes or tuberculin-unsensitized lymphocytes did not show such an inhibition. These MIF-like supernatants have been studied by Sephadex G-100 gel filtration. A MIF activity has been found for PPD and IgG supernatants between the chymotrypsinogen (MW 23,000) and the lysozyme (MW 17,000). This seems to agree with the classical region where MIF can be usually isolated.